A short cloak of the skin of the divine goat Amaltheia, bordered by snakes and with the head of Medusa in the center worn by Athena and Zeus. The Aegis could also serve as a shield and in that fashion Athena wears it upon her breastplate. It was employed as a decorative feature of the portrait busts of many of the Roman emperors. Aegis appears first on the coinage of Nero.